In typical CATV applications, a filter circuit or network is provided to pass signals having frequencies within one or more specified bandwidths, sometimes with a desired amount of signal attenuation, while blocking signals of other frequencies. It is convenient, but not necessary, to mount the electrical components such as capacitors, inductors, and resistors on one or more printed circuit boards in essentially conventional fashion. The circuit board carrying the filter circuit components is mounted within a suitable protective housing. Physical rigidity is required to maintain stable electrical response. Connection headers at each end provide for connecting the filter to a coaxial cable connector and to an equipment port. The entire assembly is commonly referred to as a filter or trap.
It is customary in the CATV industry for system technicians to use special wrenches for the installation and removal of traps. These special wrenches are of the pin spanner type where the driving pins of the wrench are accepted by two shallow holes bored into the end face of one header, sometimes referred to as engagement holes. This has been effective, but requires a degree of manufacturing difficulty and material usage which increases the cost of the trap housing components.
U.S. Pat. No. 5,150,087 (Yoshie et al.); U.S. Pat. No. 5,432,488 (Kotani et al.); U.S. Pat. No. 5,662,494 (Zennamo, Jr. et al.); U.S. Pat. No. 6,273,766 (Zennamo, Jr. et al.); U.S. Pat. No. 6,636,129 (Zennamo, Jr. et al.); U.S. Pat. No. 6,829,813 (Zennamo, Jr. et al.); and U.S. Pat. No. 6,888,423 (Tresness et al.) all show traps with the two engagement holes drilled into the end face of one of the headers.